1. Field of the Invention
The invention pertains to a stator having a yoke, a plurality of stator coils arranged on the yoke, and a plurality of mutually insulated linking conductors having terminal elements connected to ends of the stator coils.
2. Description of the Related Art
Known stators for electrical machines have a stator yoke with a number of stator teeth, which carry the electrical winding in the form of, for example, individually wound stator coils of insulated wire. The two ends of each coil are assigned to individual strands and are connected to each other in a predetermined manner by common linking conductors. In the case of a three phase machine, the stator has three strands and thus at least three linking conductors, each of which is supplied with current with a phase offset of 120°. The linking conductors are wired to a switch box so that the electrical machine can be connected to a power source.
U.S. Pat. No. 6,369,473 discloses a stator for an electrical machine in which the wiring arrangement has electrically insulated linking conductors, which are concentric with respect to each other. The terminals which accept the ends of the stator coils are in the form of projections extending from the linking conductors. For each coil end, a separate terminal projection is provided, and as a result of the radial staggering of the linking conductors thus realized here, the connecting points are also in different radial positions. The electrical connections can be realized here by a joining technique such as welding or soldering and/or by simply winding the wire around the terminal projection. The linking conductors are supported against each other and against the stator by interposed strips of insulating material.
The wiring technique explained above suffers from the disadvantage that there is a very large number of contact points, each of which must be produced individually, that is, by a separate joining procedure. It should also be remembered that the ends of the coils must be cut individually to the required length beforehand, this length depending on the radial position of the linking conductor. Overall, wiring work of this type is very time-consuming and thus cost-intensive. Because of the relatively large number of coil ends, furthermore, there is considerable danger of connecting them incorrectly when the stator coils are being connected, that is, of assigning them incorrectly to their intended linking conductors. Even if great care is taken, it is still impossible to be completely certain that all of the connections are made properly during the production of these stators.